Hybrid vehicles include a secondary battery mounted thereon for storing electric energy for driving a vehicle. The temperature of a secondary battery rises with charge and discharge due to an internal resistance of the secondary battery itself. Conventional techniques have therefore suggested providing a cooling fan around the secondary battery to forcibly cool the secondary battery.
JP 2010-158964 A, for example, discloses a cooling apparatus for vehicle electronic equipment, which includes a cooling fan near a secondary battery. This cooling apparatus changes the command duty of the cooling fan in accordance with the temperatures of a high-voltage secondary battery which are to be cooled and anon-vehicle charging device. In other words, the cooling apparatus controls driving of the cooling fan based on variable control. This cooling apparatus further detects failure of the cooling fan, and if failure occurs, outputs failure information to a failure diagnosis function unit, that is, causes the failure diagnosis function unit of a control unit to record the failure information. This cooling apparatus further changes control for the electronic equipment in accordance with the content of failure.